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Abstract Functioning ingestible capsules offer tremendous promise for a plethora of diagnostic and therapeutic applications. However, the absence of realistic and practical power solutions has greatly hindered the development of ingestible electronics. Microbial fuel cells (MFCs) hold great potential as power sources for such devices as the small intestinal environment maintains a steady internal temperature and a neutral pH. Those conditions and the constant supply of nutrient‐rich organics are a perfect environment to generate long‐lasting power. Although previous small‐scale MFCs have demonstrated many promising applications, little is known about the potential for generating power in the human gut environment. Here, this work reports the design and operation of a microbial biobattery capsule for ingestible applications. DormantBacillus subtilisendospores are a storable anodic biocatalyst that will provide on‐demand power when revived by nutrient‐rich intestinal fluids. A conductive, porous, poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate hydrogel anode enables superior electrical performance in what is the world's smallest MFC. Moreover, an oxygen‐rich cathode maintains its effective cathodic capability even in the oxygen‐deficit intestinal environment. As a proof‐of‐concept demonstration in stimulated intestinal fluid, the biobattery capsule produces a current density of 470 µA cm−2and a power density of 98 µW cm−2, ensuring its practical efficacy as a novel and sole power source for ingestible applications in the small intestine.
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Dissolvable Probiotic‐Powered Biobatteries: A Safe and Biocompatible Energy Solution for Transient Applications
Abstract For decades, science fiction has imagined electronic devices that spring to life on demand, function as programmed, and then vanish without a trace. Today, transient and bioresorbable electronics are making that vision a reality, sparking revolutionary progress in biomedicine, environmental stewardship, and hardware security. Yet one critical barrier remains: a fully transient power source with the same disappearing act. Microbial‐based biobatteries have emerged as strong contenders, harnessing the power of microorganisms—found virtually everywhere—as natural biocatalysts. However, toxicity and health risks have limited these systems to single‐use, often incinerable applications. Here, a transformative approach: a transient biobattery powered by commercially available probiotics that dissolves harmlessly is introduced, releasing only beneficial microbes. Fabricated on water‐soluble or pH‐responsive substrates, this biobattery capitalizes on a 15‐strain probiotic blend to generate electricity across diverse electrode materials. By manipulating device length or encapsulating it with pH‐sensitive polymers, power delivery can be fine‐tuned from 4 min up to over 100 min. A single module outputs 4 µW of power, 47 µA of current, and an open‐circuit voltage of 0.65 V. This groundbreaking design ushers in a new era of safe, effective transient bioenergy systems, opening unprecedented opportunities in biomedical implants, environmental sensors, and disposable electronics.
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- PAR ID:
- 10579547
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Small
- Volume:
- 21
- Issue:
- 19
- ISSN:
- 1613-6810
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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